assume any corporation collecting information is sharing it with other corporations | even perceived competitors

The insurance industry wants to know what your HMO knows.

The credit industry wants to hear from the card you paid late so it can Universally Default you.

As DeNiro says in that bad/good movie "Heat," "Assume they know everything."

In other words, when you give out information - assume you are giving it to the person in front of you, their superior, the corporation who runs their superior, every management decision that will be made after the current management leaves and their crappy replacements come in, and most of all: Your information will be used by any corporation for this purpose: To increase their bottom line.

If that means selling your information to a competitor and that's what the board tells them to do when they go bankrupt (a corporate fire sale), than your information gets disseminated.

The only guarantee from Corporate America is this: They will use anything they have, they will do anything within their power in order to fulfill their only mission: Increase quarterly profits.

If that doesn't scare you, it should.